One method of producing an integrated circuit arrangement includes the application of a dielectric layer to an electrode layer which contains at least one electrode. Followed by application of a resist layer, structuring of the dielectric layer, and removing residues of the resist layer.
At a temperature of 20° C., the dielectric layer has an electrical resistivity of, for example, more than 1010 Ωcm or even 1016 Ωcm. By way of example, silicon dioxide is used as the material for the dielectric layer. However, materials with a dielectric constant of more than 3.9 are also used, for example silicon nitride, aluminum oxide or tantalum pentoxide.
In contrast, the electrode layer contains a highly conductive material which has an electrical resistivity of less than 10−4 Ωcm, for example. However, the electrical resistivity is usually one or more orders of magnitude less than this value. Examples for materials in the electrode layer are aluminum, aluminum alloys, copper, copper alloys, silver, titanium or other metals or compounds such as tantalum nitride TaN or titanium nitride TiN.
By way of example, the resist layer could be removed once the dielectric layer has been completely structured with the aid of the resist layer. However, this has the disadvantage that, during the removal of the resist, parts of the electrode layer are exposed and are thus attacked by the chemical processes which are used to remove the resist. The removal of the photoresist is carried out, for example, by carbonization at a temperature of about 200° C. and subsequent removal of the ash using a solvent. Alternatively, it is possible to remove the photoresist just by means of a wet-chemical process.
By way of example, the material of the electrode layer may be oxidized. The oxidation products which are produced in this way must be removed again by means of a specific cleaning step. This cleaning step must be specifically developed and optimized, in particular when specific oxides must be removed, for example copper oxides. If the reaction products which are produced during removal of the resist on the electrode layer are not removed completely, then this leads to high contact resistances, resulting in a deterioration in the reliability of the electrically conductive connections.
Furthermore, the chemical compounds which are produced during removal of the resist in the area of the exposed regions of the electrode layer also penetrate under the dielectric layer. Underetching thus occurs during removal of the reaction products, making the electrical characteristics of the integrated circuit arrangement considerably worse. For this reason as well, considerable funds must be invested in the development of the cleaning step.